[linux-dvb] Re: DVB + SATA

[Manu Abraham <manu@kromtek.com>]

On Wednesday 04 Aug 2004 3:44 am, Ben de Luca (bedel) wrote:
> I have two of these cards and have to set the pci latency ridiculously
> low on all other cards (<32) to get it not to continually break up.
>
> then i can run 2 cards fine
>

		I think that explains it. The twinhan cards needs to hane a haigher latency 
64 or higher. For me 64 and or 128 works good. Larger latency values work 
well, but definitely not smaller.

Regards,
Manu


> On 31/07/2004, at 5:19 PM, Manu Abraham wrote:
> > On Thursday 29 Jul 2004 4:29 pm, Johannes Stezenbach wrote:
> >> Tim wrote:
> >>> It appears that boards with the Intel SATA controller built in to the
> >>> south bridge don't have any problems.
> >>>
> >>> With the NF7-S and VP DVB-t, some fiddling with PCI latency settings
> >>> improves matters a little, but it is still unwatchable when
> >>> recording. I
> >>> think the VisionPlus is a lost cause.
> >>>
> >>> I'm still trying to find a DVB-t card that is likely to work with the
> >>> NF7-S V2.0 and SATA. Any more comments? I'm thinking of shelling out
> >>> for
> >>> a DVICO card in the hope that it will be more reliable.
> >>
> >> There's the possibility that the power supply isn't
> >> stable enough. DVB frontends are quite sensitive in
> >> that area.
> >>
> >> Another possibility which was discussed recently on lkml is
> >> that large IDE DMA transfers are a source of high irq latency
> >> (i.e. the DVB card misses some irqs). But I guess the
> >> DVB driver would spit out error messages in this case.
> >> You could try to lower max_s from 2048 to e.g. 128 in
> >> linux/drivers/ide/ide-disk.c:idedisk_setup() to find out.
> >
> > 	Before making a final conclusion, why not check up the connection to
> > the LNB
> > ? There can be problems on bad connectors as well -- if the shield
> > does not
> > have a good connection with the connector. Earlier somebody had a
> > similar
> > problem with the same symptom, the only difference in that case was,
> > when the
> > machine was getting heated up.
> >
> > 		The entire cable run could be checked up for possible problems before
> > jumping into conclusions.
> >
> > 		I had CRC errors when i had bad splitters. Just make sure it is the
> > IDE DMA
> > controller itself. I had problems when i tried to reduce latency to
> > less than
> > 64. Eventhough Twinhan suggests 256.
> >
> > 		One more case is there, the vision plus cards are claimed to have
> > problems
> > with some VIA chipsets and some Triton chipsets by the manufacturer
> > itself. I
> > don't know which motherboards do carry these chipsets. What info i got
> > was it
> > was due to the bad timing on the chipset.
> >
> >
> > Regards,
> > Manu
> >
> >> Johannes